Cooling apparatus



June 16, 1936. E. F. STALCUP 2,044,644

COOLING APPARATUS Filed Aug. 10, 1954 WRTER LEVEL "1 INVENTOR ERNEST F.STRLCUF.

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ATTORNEY Patented June 16, 1936 COOLING PARATUS Ernest F. Stalcup,Rutledge, Pa, assignor'to Westinghouse Electric & Manufacturing Company,East Pittsburgh, Pa., a corporation of Pennsylvania Application August10, 1934, Serial No. 739,216

11 Claims. (Cl. 62-452) My invention relates to cooling apparatus of thetype known as thermal compressor, or vapor jet refrigerating apparatusand it has for an object to provide an improved control therefor.

A further object of this invention is"to terminate operation of a vaporjet refrigerating machine in response to abnormal operating conditions.I

Vapor jet refrigerating apparatus usually in- '10 cludes one or moreejectorsmotivated by a fluid,

for example, steam, for maintaining a high vacuum in a chambercontaining water, or other medium to be cooled. The water is admitted tothe chamber, usually by spraying, and a portion of the water isvaporized at relatively low temperatures due to the low pressuremaintained in the chamber. The latent heat of vaporization of theportion which is vaporized is abstracted from the remaining portion,thereby cooling the same.

The water vapor is entrained by the ejectors, compressed, and dischargedinto a condenser. cooled water in the cooling chamber may be circulatedto a point of use for refrigerating purposes.

Faulty operation of the apparatus, such as inadequate vacuum in thecondenser, may result in back flow of the relatively high temperaturemotive fluid from the ejectors into the evaporating chamber and heatingof the water or other liquid which is to be cooled. In' accordance withmy invention, I automatically terminate operation of the ejectors whenback flow of motiv uid into the evaporating chamber occurs, in ccordancewith a predetermined maximum temperature within the evaporating chamber.Undue heating of the water is thereby prevented. The operation of theejectors may also be terminated in response to a predetermined minimumtemperature to prevent freezing of the water.

These and other objects are effected by my invention, as will beapparent from the following description and claims taken in connectionwith the accompanying drawing, forming a part of this water, .to thechamber for cooling and the cooled which communicate with the chamberl0. Vapor discharge portions l1 and ill of the respective ejectorsconnect with a condenser l9. Vapor 10 valves 2! and 22 may be connectedbetween the ejectors l3 and i l and the evaporating chamber ill toprevent reverse flow of vapor from the condenser l9 to the chamber l0,when their respective ejectors are shut down. 15

Motivating fluid, for example, steam, is supplied to the nozzles (notshown) of' the ejectors I3 and It from a header 23 through branchconduits 24 and 25, respectively. A main steam valve 26 is arrangedbetween the header 23 and a steam 2o supply pipe 2'! for controlling theflow of steam from the latter to the former. Valve 26 may be operated inany convenient manner as by a solenoid 28. 'Flow of motivating steamthrough the conduits 24 and 25 is controlled, respectively, by 25 valves29 and 3! which are preferably electrically operated. Electricaloperating mechanisms, such as, for example, solenoids 32 and 33 may beemployed for actuating the valves 29 and 3i. In

connection with the operation of the valves 26, 30

29, and 3t, it will be understood that they are open when theirrespective operating mechanisms or solenoids are energized, and,conversely, are closed when their solenoids are deenergized.

The condenser l9 may be of a conventional 35 water-cooled type havinginlet and outlet connections 35 and 36, respectively, for cooling water.An ejector3l may be employed for maintaining a suitable condensingpressure within the condenser 19. Motivating fluid for the ejector 31 40is conveyed thereto by means of a conduit 38 from the steam supply pipe21 and is preferably controlled by a hand valve 38A.

Energization of the solenoids 32 and 33 may be controlled by means of aswitch 39 having a movable contact 4| and stationary contacts 42 and 43,the latter contacts being so arranged that engagement thereof by themovable contact M is effected in sequence. Contacts 42 and 43 areconnected to their respective solenoids 32 and 33 by conductors 44 and45. The solenoids 32 and 33 are connected to one conductor Ll of asource of power by means of a conductor 46 and the opposite conductor L2of the power source is conniacted by a conductor 41 to the movablecontact 4 Engagement of the contacts 42 and 4| energizes the solenoid 32through a circuit including line conductor L2, contacts 4| and 42,conductor 44, solenoid 32, conductor 46, and line conductor L|. Thesolenoid33 is energized when contacts 4| and 43 are engaged through acircuit similar to the one traced, but including conductor 45. It willbe apparent that, when the switch 39 is so adjusted, contacts 4| and 42are engaged, the ejector l3 operates. Further adjustment of switch 39toa position where contacts 4| and 43 engage efiects operation of bothejectors l3 and M.

The switch 39 may be manually operated but I prefer that it beautomatically operated in response to temperature of the cooled water. Athermostatic element is therefore disposed in heat exchanging relationwith the cooled water in conduit l2 adjacent the chamber Ill. Theelement 50 is connected to an expansible bellows 48 by a tube 49. Theelement 50, tube 49, and bellows 48 define a closed chamber in which anexpansible or volatile fluid is enclosed. Thermostats of this type arewell known in the art, and no further description of the same is deemednecessary. The thermostat functions to maintain a predetermined meantemperature within the chamber l0. When the temperature within thechamber is at a predetermined value, for example, 42, the bellows 48 iscontracted and movable contact 4| is out of engagement with contacts 42and 43. Accordingly, the ejector valves 39 and 3| are both closed. Asthe temperature within the chamber increases to 43, the contact 4|engages contact 42 thereby starting ejector l3 and further increase intemperature elfects closure of contacts 4| and 43 for initiatingoperation of ejector |4. It will be understood that the vapor valves 2|and 22 are opened when their respective ejectors l3 and I4 are startedand are closed as their associated ejectors are stopped. These valves 2|and 22 are preferably operated sequentially with respect to the steamvalves associated with their ejectors. For example, as operation of theejector I3 is initiated,'the steam valve 29 is first opened, and, aftera time interval has elapsed, the valve 2| opens. In terminatingoperation of the ejector 3, the vapor valve 2| is closed first and thesteam valve 29 last. The mechanism for effecting the sequentialoperation of the steam and vapor valves forms no part of my inventionand has not been disclosed. A mechanism for this purpose is disclosedand claimed in the copending application of D. W. R. Morgan, Serial No.694,510, filed October 20, 1933 and assigned to the WestinghouseElectric 8a Manufacturing Company.-'

During normal operation, the ejectors l3 and I4 are rendered activeand'inactive by the thermostatically operated switchj39 in accordancewith predetermined temperatures to be maintained within the chamber l0.Abnormal conditions may develop during which the temperature mayincrease beyond or decrease below the desired temperatures to bemaintained. These abnormal conditions may be due to defectiveoperationof one or more of the various elements of the cooling system.For example, the steam jet in an ejector may break due to low steampressure or high condenser pressure, so that hot steam backs up intothe, chamber l0 and increases the temperature therein above a desiredvalue. Defective operation of the thermostat or the switch 39 may causeprolonged operation of the ejectors and decrease the temperature withinthe chamber l0 to an undesirable, and possibly freezing value.

In order to preclude these undesirable abnormal temperatures, I providea thermostatic device 5| responsive to predetermined high and lowtemperatures within the chamber I!) for terminating operation of theejectors l3 and I4. Preferably, the device 5| operates switches 52 and53 connected in the conductors 44 and 45. The

operation of the thermostatic device 5| is such, that the switches 52and 53 are closed during normal operation of the apparatus but areopened when the temperature within the chamber exceeds a predeterminedhigh value, for example 60, or a predetermined low value, for example35.

The thermostatic device 5| may include an expansible bellows 54connected by a tube 55 to a bulb 56 disposed, preferably, in the vaporspace within the chamber ID. The switches 52 and 53 have elongatedstationary contacts 51 over which bridging members 58 slide, thearrangement being such that the bridging members 58 engage theirrespective stationary contacts when the temperature of the bulb 56 isbetween 35 and 60. As the temperature within the chamber I0 rises above60, the bellows 54 expands, moving the bridging members 58 to the rightas viewed in the drawing, and disengages them from the stationarycontacts 51. Decreasing the temperature of the chamber |0 below 35causes the bellows 5'4 to contract and move the bridging members 58 tothe left and out of engagement with the contacts 51.

Assuming the ejectors l3 and M are operating to withdraw vapor from thechamber Ill and that one or both of the jets break due to a lowmotivating steam pressure, the hot steam will flow from the ejectorthrough the vapor inlet thereof to the chamber l0. As the thermostaticbulb 56 is arranged in the vapor space in the chamber l0, it immediatelyreflects the rapid change in temperature, and the bellows 54 operates toopen the switches 52 and 53. The valve solenoids 32 and 33 aredeenergized so that the valves 29 and 3| close, and-flow of steam to thechamber -|0 is stopped. The temperature within the chamber l0 may thendrop to below 60 due to the cold water therein, and close the switches52 and 53.

Control of the valves 29 and 3| is thereby returned to thethermostatically operated switch 39. If the temperature of the chamberI0 remains above the operator may start operation of the ejectors bymanually energizing the solenoid circuits in any manner, as, by manuallyholding the switches 52 and 53 closed until the temperature in thechamber II) drops below 60. If the temperature of the chamber I0 isdepressed below 35 due, for example, to the failure of switch 39 toopen, the bellows 54 contracts and switches 52 and 53 open therebyterminating operation of the ejectors l3 and M. The latter are againsubjected to the controlling action of the thermostatic switch 39 whenthe temperature of the chamber |0 rises above 35, at which temperaturethe switches 52 and 53 close.

It may be desirable to so arrange the control apparatus that manualattention is required before the thermostatic switch 39 is conditionedto open position by the bellows 53 in response to abnormal high or lowtemperatures in the chamber W. The latch 60 includes a bolt 6|, movablewith the bridging members 58 and a movable latch 62. The latter ispivoted at 63 to a fixed member and has slots 64 and 65 formed therein.

'low abnormal temperatures.

Normally the bolt 6! rides back and forth on the latch 62 between theslots but, when the bellows 54 operates to open the switches 52 and 53,the bolt 6| aligns with one or the other of the slots 64 and 65, and thelatch 62 is moved upwardly by a spring 66. This movement locks the bolt69 in the latch and prevents return movement of the bellows 54 andclosure of the switches. Before the system can be conditioned foroperation, the operator must depress the latch 62 for releasing the bolt6|. The switches 52 and 53 may then close.

In Fig. 2, I show a modified control system in which the thermostat 5|operates a single switch it connected in circuit with the solenoid M ofthe main steam valve 26. The solenoids 3'2 and 33 of the ejector valves26 and 3| are controlled by the switch 39 and are not subject to controlby the thermostat 5!. In this. embodiment, flow of motivating steam fromthe supply pipe 21 to the ejectors I 3 and I4 is terminated in responseto abnormal temperatures obtainlng in the chamber Ill, as opening of theswitch 10 deenergizes the solenoid 28 of the valve 26. In thisembodiment, as in the prior one, the latching device of Fig. 3 may beapplied to the thermostat 5i and switch ill.

In both embodiments, flow of motivating steam to the ejector 31 shouldnot be interrupted during periods when the apparatus is operative, as itis desirable to maintain a suitable condensing pressure in the condenserat such times. The conduit 38 is" therefore connected directly to thesteam line 21 and is not controlled by any of thethermostatically-operated valves 29, 3|, or 26.

From the foregoing, it will be apparent that I have devised improvedvapor jet refrigerating apparatus which may be manually or automaticallycontrolled to maintain liquid at a substantially constant temperatureand which may .be rendered inactive when the temperature of the liquidor vapor therein attains predetermined high or I have disclosedelectrically operated controlling mechanisms for actuating variouselements oi. my improved apparatus but my invention is not to be limitedthereto as other forms of controlling devices may be employed.

while I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleoi! various other changes and modifications without departing from thespirit thereof, and I desire, therefore, that only such limitationsshall be placed thereupon as are imposed by the prior art or as arespecifically set forth in the appended claims. I

What I claim is:

1. In cooling apparatus, the combination of an evaporating chamber forreceiving liquid to be partially evaporated and cooled, ejecting meansfor withdrawing vapor from said chamber, and means responsive to apredetermined maximum temperature within said chamber for rendering saidejecting means inefiective to withdraw vapor for withdrawing vapor fromsaid chamber, and means responsive to predetermined minimum and maximumtemperatures within said chamber for rendering the ejecting meansineffective to withdraw vapor from the chamber.

3. In cooling apparatus, the combination of an evaporating chamber forreceiving liquid to be partially evaporated and cooled,ejecting meansfor withdrawing vapor from said chamber, means responsive topredetermined high and low temperatures within the chamber forrespectively initiating and terminating operation of said ejectingmeans, and means responsive to predetermined temperatures, one of whichis higher than said predetermined high temperature and the other ofwhich is lower than said predetermined low temperature, for terminatingoperation of the ejecting means.

5. In cooling apparatus, the combination of a chamber for receivingliquid to be partially evaporated and cooled, an ejector for withdrawingvapor from said chamber, means for controlling the supply of motivatingfluid to the ejector, means responsive to predetermined high and lowtemperatures within said chamber for actuating said last-named means,and means responsive to predetermined temperatures, one of which ishigher than said predetermined high temperature and one of which islower than said predetermined low temperature, for actuating themotivating fluid controlling means to terminate operation of theejector.

6. In cooling apparatus, the combination of an evaporating chamber forthe reception of liquid to be partially evaporated and cooled, aplurality of ejectors for withdrawing vapor from said chamber, means forselectively controlling the operation of the ejectors, and meansresponsive to a predetermined high temperature within saidchamber forterminating the operation of all of the ejectors.

"I. In cooling apparatus, the combination of an evaporating chamber forthe reception of liquid to be partially evaporated and cooled, aplurality of ejectors for withdrawing vapor from said chamber, meansresponsive to predetermined temperatures within said chamber, forcontrolling the operation of at least one of the ejectors, and meansresponsive to a predetermined low temperature within said chamber forterminating operation of all of the ejectors.

8. In cooling apparatus, the combination of an evaporating chamber forthe reception of liquid to be partially evaporated and cooled, aplurality of ejectors for withdrawing vapor from said chamber, meansresponsive to predetermined temperatures within'said chamber, forselectively controlling the operation of the ejectors, and meansresponsive to abnormal high and low temperatures within said chamber forterminating the operation of all of the ejectors.

9. In cooling apparatus, the combination of'an evaporating chamber forthe reception of liquid to be partially evaporated and cooled, aplurality of ejectors for withdrawing vapor from said chamber, a sourceof motivating fluid for the ejectors, means associated with each of theelectors for controlling the flow of motivating fluid -thereto, andmeans responsive to a temperature within said chamber which is afunction of an abnormal condition for terminating the flow of motivatingfluid to the ejectors independently of the last-named means.

10. In cooling apparatus, the combination of an evaporating chamber forthe reception or liquid to be partially evaporated and cooled, aplurality of ejectors for withdrawing vapor from said chamber, a sourceof motivating fluid for the ejectors, a header, means for controllingthe flow of motivating fluid from said source to said header, aplurality of valves connected, respectively, between said header and theejectors, means responsive to normal temperature conditions within saidchamber for controlling at least one of said valves, and meansresponsive to abnormal temperature conditions within said chamber foractuating the first-named means to terminate flow of motivating fluid tothe header.

11. In cooling apparatus, the combination of an evaporating chamberadapted to contain liquid, an ejector for withdrawing vapor from saidchamber to eilect cooling by evaporation of liquid, means forcontrolling the admission of motive fluid to said ejector in accordancewith the cooling demand on the cooling apparatus, and

means operable in response to an operating condition of the coolingapparatus substantially concurrent with and indicating back-flow ofmotive fluid from said ejector into said chamber for shutting ofl theadmission of motive fluid to said ejector.

ERNEST F. STALCUP.

